The P2520: A/C Request ‘A’ Circuit Low refers to a problem in the A/C request circuit ‘A’ where the voltage or signal is lower than expected. This could be due to a faulty A/C request control module, issues in the wiring, or connector problems. A low voltage in the A/C request circuit can prevent the air conditioning system from engaging properly, resulting in reduced cooling performance.
P2520 – Quick Overview
Code | Information |
---|---|
Meaning | P2520: A/C Request ‘A’ Circuit Low |
Is it serious? | Moderately serious. This can prevent the A/C system from functioning properly, affecting cooling performance and passenger comfort. |
Possible causes | – Low voltage or signal in the A/C request ‘A’ circuit – Faulty A/C request control – Wiring or connector issues |
How to diagnose? | – Measure the voltage in the A/C request ‘A’ circuit – Inspect and test the A/C request control – Check wiring and connectors – Replace faulty components if needed |
Code Meaning
The P2520: A/C Request ‘A’ Circuit Low code indicates that the voltage in the A/C request circuit ‘A’ is below the specified range, potentially due to insufficient power supply, faulty control module, or wiring problems. The A/C request circuit is responsible for initiating the air conditioning system when cooling is required. A low signal prevents the system from functioning as intended.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for any additional related codes. These codes might provide more context or clues regarding other issues within the A/C system. | OBD-II Scanner |
Measure Voltage in the A/C Request ‘A’ Circuit | Use a multimeter to measure the voltage at different points in the A/C request circuit ‘A’. Compare these readings with the manufacturer’s specifications to determine if the voltage is too low. | Multimeter |
Inspect the A/C Request Control Module | Visually inspect the A/C request control for any visible damage or corrosion. Ensure that the control module is securely mounted and properly connected. | Flashlight, Safety Gloves |
Check Wiring and Connectors | Examine all wiring and connectors related to the A/C request circuit ‘A’. Look for frayed wires, loose connections, or corrosion that could be causing a voltage drop. Repair or replace any damaged wiring or faulty connectors. | Flashlight, Multimeter |
Test the A/C Request Control | Use a diagnostic tool or multimeter to test the A/C request control. Verify that the control module is capable of sending the correct signal when the A/C is engaged. Replace the module if it is unable to provide the proper voltage output. | Multimeter, Diagnostic Tool |
Verify Power Supply and Ground | Ensure that the A/C request circuit has a reliable power supply and is properly grounded. Insufficient power or a faulty ground can lead to a low voltage condition. | Multimeter |
Replace Faulty Components | Replace any faulty components found during diagnostics, such as the A/C request control module, connectors, or wiring. Make sure to use parts that meet OEM specifications for compatibility and reliability. | Replacement Parts, Vehicle Owner’s Manual |
Clear the Code and Test the A/C System | After making repairs, clear the P2520 code using an OBD-II scanner. Run the A/C system to ensure that it functions correctly, and verify that the request circuit is working as intended. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle to ensure that the P2520 code has not returned. If the code persists, further diagnostics will be needed to determine additional underlying issues. | OBD-II Scanner |

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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)